Fuel Efficiency

[nw-mailing-list at nwhs.org]

Ed:  Fuel efficiency between steam and diesel would be the specific fuel
consumption in lbs. per hp per hr.

 

In general terms, the diesel will have much better thermal efficiency-
better use of the heat created for some simple reasons based on the
overall cycle temperatures.  No to drift off into a general discussion
of the thermodynamics, but the thermal efficiency is a function of the
temperature differences in the cycle.  In this case, it is the burning
temperature of the diesel fuel and its exhaust temperature (like 3000
degrees F to about 400 degrees F) compared to the peak superheated steam
temperature of about 900 degrees then down to about 150 F after
expansion.  That the diesel burns its expanding gas directly where the
steam locomotive burns outside its steam and adds heat to the steam
makes a big difference.  That heat transfer step causes a lot of losses.

 

Once you add the heat to the expanding gas, you have to look at
converting that energy packed into the gas/steam into mechanical work.
This conversion process (cylinders, rods and wheels or electrical
generation and conversion to rotary motion in the motors) has many
inefficiencies.

 

Roughly you are converting 3-6% of the energy into useful work.  Modern
diesel-electrics with computer controls probably convert 6 to 12 % of
the energy into useful work.  Steam or Diesel, it is REALLY important to
run at the optimum output speed and conditions to keep the overall fleet
usage of fuel at the most efficient.  The illustration is the C&O
running the H-8 Alleghanies as luggers; they were bleeding money in the
fuel bills.  Steam or diesel, it is REALLY important to run at constant
speed especially at the unit's optimum speed.  Very tough to run the
railroad and achieve that!  

 

By the way, the N&W took great pains to arrange the trackage to achieve
the optimum speed over the road.  That is the main reason for owning the
dynamometer car!  I have file from the N&W in the 1920's where they
measured Y-3's performance hauling the coal trains through Chillicothe,
Ohio with the sole purpose of determining how to revise the curves and
grades so that the locomotive did not slow down past its optimum speed
range.

 

See the past ARROW articles on the EMD Class A and Class Y-6 tests to
get the details of the performance in those days. 

 

G Rolih, Cincinnati 

 

-----Original Message-----
From: nw-mailing-list-bounces at nwhs.org
[mailto:nw-mailing-list-bounces at nwhs.org] On Behalf Of
nw-mailing-list at nwhs.org
Sent: Wednesday, January 25, 2006 11:30 PM
To: NW Mailing List
Subject: Re: Whither the Link and Pin ?

 

N&W did many studies of this type.  I believe one is in the new N&W -
GIANT OF STEAM.  It was in the old one, too.

 

EdKing

	----- Original Message ----- 

	From: nw-mailing-list at nwhs.org 

	To: nw-mailing-list at nwhs.org 

	Sent: Wednesday, January 25, 2006 7:34 PM

	Subject: Re: Whither the Link and Pin ?

	 

	Not much has changed I guess. Kind of like fuel economy numbers
in cars.  Speaking of fuel economy, has anyone ever looked at the fuel
efficiency of steam (ie coal) vs. diesel fuel on a strictly fuel
efficiency basis?  That is, don't take into consideration maintenance on
steam vs. diesel motive power?

	Ed Svitil

		
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		From: nw-mailing-list at nwhs.org
		Reply-To: NW Mailing List <nw-mailing-list at nwhs.org>
		To: "NW Mailing List" <nw-mailing-list at nwhs.org>
		Subject: Re: Whither the Link and Pin ?
		Date: Mon, 23 Jan 2006 23:46:46 -0500

		Abram,

		 

		I read an article recently in "American Heritage of
Invention & Technology (magazine), Winter 2006, Vol.21, No.3.

		 

		The article entitled "The Strongest Handshake in the
World" was written by John H. White, Senior Historian Emeritus at the
Smithsonian Institution, and professor of history and mechanical
engineering at Miami University, in Oxford, OH.

		 

		A very interesting article about Mr. Janney, inventor,
and Mr. Lorenzo Coffin, who took up the "cause", and finally got the
coupler mandated by law.

		 

		He states that President Harrison signed the Safety and
Appliance Act on March 3, 1893, his last full day in office.  This act
also made air brakes mandatory.  "Railroads were given five years to
complete the transition."  By that date, 1898, only 68% of cars had the
new couplers.  They were granted an extension to Jan. 1900, then another
eight months after that!  He says that "by 1900 coupler related injuries
dropped from 32% to 9% of all injuries", and then to 4% in 1902.

		 

		Like many inventors, Janney did NOT get rich from his
life-saving invention.

		 

		Jeff Sanders

		----- Original Message ----- 

			From: nw-mailing-list at nwhs.org 

			To: NW Mailing List
<mailto:nw-mailing-list at nwhs.org>  

			Sent: Sunday, January 22, 2006 5:47 PM

			Subject: Re: Whither the Link and Pin ?

			 

			Asketh Jim Kehn:

			 

			>> Everytime I see one of those I wonder how
those old timers ever switched a train. You must have had to hold the
link up to enter the pocket of the other coupler and use the other hand
to insert the pin. How in the world did they give a stop signal, etc??
<<

			 

			 

			Well, Jim, "the literature" speaks of trainmen
using a stick in one hand to hold up the link and guide it into the
pocket of the standing car, and using the other hand to drop in the pin.
Of course, one had to be between the cars to do it.

			 

			I have seen several good line drawings of
trainman using link and pin couplings over the years (invariably copied
out of publications like Leslie's Weekly &c,) but I couldn't point you
to one at the moment.

			 

			The Railway Safety Appliance Act of 1893 (or was
it 1892???) took aim at the link and pin coupler and also addressed such
things as ladders, stirrups and brake wheels.  The railroads screamed
bloody murder and implementation date for the provisions of the Act was
extended several times.  By the end of the decade, I'd imagine that
everything running on the main lines had been replaced by Janney
couplers.

			 

			To get a fix on the date that railroads made a
commitment to the change-over, I once sat down with the builders
photographs from Altoona Works and looked for the first engine
outshopped with a Janney coupler on the front end.  It was the Spring of
1893... April, as I recall.  That should be a good index for practices
in the industry.

			 

			As for how one would "wave down" the engineman
while both of his hands were engaged in coupling, you got me.  But
remember that switching crews back then had three, four and five
brakemen on them (just look at the old photographs,) so perhaps one
stood outside the coupling and gave the signal.  I'm just guessing.
(And road trains had a third brakeman who was called "the Middle Man,"
who "hand broke" the cars in the middle of the train.)

			 

			As a young kid, I knew a man who had hired in
1896 on the Roanoke & Southern/Punkin' Vine, or whatever you want to
call it.  (He called it the "Roanoke & Southern.")  He told me some
interesting things, viz. that when the crew was heading out to their
train after reporting for duty, everyone grabbed as many links and pins
as he could carry, and put them on the engine and caboose... because
they knew they would need them.  Another thing he told me was that ashes
from the coal stove were a valuable comodity, and were stored until
needed under the bunks on the caboose.  During snow and icy conditions,
a trainman "on the tops" would carry a bucket and scatter them on the
running boards of those cars in the train which he was "braking," to
assist in avoiding falls.  Oh, I wish I had had the questions then that
I have now, and could ask that old gentleman !

			 

			-- abram burnett

			        (also an old trainman)

			 

			
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